Codesign Case Study of a Planing Craft with Active Control Systems

Abstract

This case study presents a novel insight into the design of a codesigned planing craft with an active control system (ACS), along with its potential advantages and disadvantages when compared with a traditionally designed vessel (i.e., a vessel whose geometry is first selected, and then its ACS is implemented). This work has three purposes:present tools a designer can use to codesign a planing craft with its ACS,use these tools to expand the design space and further explore the potential of codesign, andinvestigate the feasibility of having a planing craft with ACS designed to the codesign results found in 2) and compare it with a traditionally designed vessel. The vessel particulars that are numerically optimized are the beam, dead rise, longitudinal center of gravity (lcg), and two tuning parameters for the ACS's linear quadratic regulator. In the case study, the codesigned vessel had 4% lower drag at the design speed and Sea State (SS) 3, but on lower SS's it had drag savings of 10% and seakeeping improvements of around 40% for the investigated seakeeping metric. The case study suggests that although the codesigned vessel is technically feasible, it would require unconventional hull/deck design—a result which emphasizes the importance of considering the coupling between a planing craft and its ACS early in the concept design. In search for a better performing planing craft, a naval architect could consider using an active control system (ACS) on their designs. Although they will encounter published research confirming performance improvements when an ACS is used (Wang 1985; Savitsky 2003; Xi & Sun 2006; Kays et al. 2009; Engle et al. 2011; Hughes & Weems 2011; Rijkens et al. 2011; Shimozono & Kays 2011; Rijkens 2013), literature addressing the concept design process of a planing craft that will have an ACS is, to the best of the authors' knowledge, limited only to the previous work by the authors (Castro-Feliciano et al. 2016, 2018). The work by Castro-Feliciano et al. (2016, 2018) suggests that the benefit from codesigning (as opposed to sequentially designing the vessel geometry and later adding an ACS) can be significant and should be the design methodology followed when designing a planing craft that will have an ACS.